public class LinkedList implements IMyList {
     @Override
     public void addFirst(int data) {

     }

     @Override
     public void addLast(int data) {

     }

     @Override
     public boolean addIndex(int index, int data) {
          return false;
     }

     @Override
     public boolean contains(int key) {
          return false;
     }

     @Override
     public void remove(int key) {

     }

     @Override
     public void removeAllKey(int key) {

     }

     @Override
     public int size() {
          return 0;
     }

     @Override
     public void display() {

     }

     @Override
     public void clear() {

     }
     //头插法

 }